Gas-Drilling Leaks Overstated

Natural gas drilling sites aren't leaking as much methane into the atmosphere as the federal government and critics of hydraulic fracturing had believed, says the Wall Street Journal.

The study, led by researchers at the University of Texas at Austin and published by the Proceedings of the National Academy of Sciences, is likely to ease some concerns about the impact of natural gas extraction on the climate.

Measuring emissions at 190 sites, the study found less "fugitive methane" than previous work by the Environmental Protection Agency (EPA) and some university researchers, which relied on estimates.

Methane, the primary ingredient in natural gas, is a potent greenhouse gas.

The measurements of gas emissions found that wells emitted about 20 percent less greenhouse gases than the EPA had estimated -- which is less than the amount emitted by burning coal.

The study also found much higher-than-expected leakage from pneumatic switches, which are used to turn equipment on and off at well sites.

David Allen, a chemical engineering professor at the University of Texas and lead researcher, said he believed the better data will help guide policymakers.